(a) Field of the Invention
The present invention concerns a process for the production of gaseous oxygen under a so-called high pressure which may vary with time, in which the gaseous oxygen is produced under a medium pressure which is higher than atmospheric pressure but lower than said high pressure, the medium pressure may vary with time, after which the pressure of this gaseous oxygen is raised to the above-mentioned high pressure.
(b) Description of Prior Art
Some processes for the production of oxygen do not permit to directly producing this gas under high pressures of the order of 10 to 15 bars. In particular, the process for the separation of air by adsorption PSA (Pressure Swing Adsorption), which utilises the properties of preferential adsorption of nitrogen by certain zeolite molecular sieves (type 5A or 13X), enables producing oxygen up to a content of the order of 95%. However, the performances of this process decrease when the highest pressure of the adsorption cycle exceeds a few bars. It is then necessary to compress the oxygen produced (this term will designate pure oxygen or a gas with a high oxygen content) by means of an oxygen compressor to reach the high pressure desired.
Oxygen compressors are apparatuses which are much more expensive than air compressors and require highly developed safety measures. Thus, the cost associated with such a compressor can represent up to 25% of the total investment for a PSA installation.
It is an aim of the invention to make it possible to dispense with the oxygen compressor.